The Dana-Farber/Harvard Cancer Center (DF/HCC) is a Harvard-wide, NCI-designated Comprehensive Cancer Center. This training grant is the principal instrument of basic science training at DF/HCC. Our broad goal is to teach young scientists at the predoctoral and postdoctoral levels how to apply emerging technology in genomics and proteomics to fundamental problems in cell division, cell differentiation or cell death (the three D's of cancer cell biology) that underlie human neoplastic disease. We propose to appoint 5 predoctoral and 12 postdoctoral scientists per year. Our pre-doctoral trainees will be selected from a pool of students who have enrolled in a newly created Cancer Biology Track in the Harvard Biological and Biomedical Sciences. These students will be appointed after their second year of study when they have completed laboratory rotations and chosen one of our mentors as their thesis advisor. The postdoctoral appointments will be for recent recipients of the Ph.D. or M.D./Ph.D. degrees. We are especially selective with our postdoctoral appointments. By multiple metrics the postdoctoral trainees appointed to our program in years past have been every bit as successful as postdoctoral fellows supported by individual awards from other funders, such as NRSA, ACS and Damon-Runyon. Funding for Clinical training is excluded from this program. Laboratory training in cancer research is complemented by a didactic program that prepares our students to exploit a broad range of job opportunities in settings ranging from the small liberal arts college, to academic medical research institutes and the biotechnology industry. Programs provided by the Postdoctoral and Graduate Student Affairs Office at Dana-Farber, which are available for all our trainees, enhance trainee cohesiveness and program identity. The didactic and one-one-one training is complemented by retreats and poster sessions that draw students, postdocs and their mentors from all major components of DF/HCC. On a tactical level, each Department/Division within DF/HCC has journal clubs and seminar programs that provide a sense of local community.